/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.localconfignode;

import org.apache.iotdb.commons.consensus.DataRegionId;
import org.apache.iotdb.commons.exception.IllegalPathException;
import org.apache.iotdb.commons.path.PartialPath;

import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

// This class is used for data partition maintaining the map between database and
// dataRegionIds.
@Deprecated
public class LocalDataPartitionInfo {

    // storageGroup -> LocalDataPartitionTable
    private Map<PartialPath, LocalDataPartitionTable> partitionTableMap;

    private static class LocalDataPartitionTableHolder {
        private static final LocalDataPartitionInfo INSTANCE = new LocalDataPartitionInfo();

        private LocalDataPartitionTableHolder() {
        }
    }

    private LocalDataPartitionInfo() {
    }

    public static LocalDataPartitionInfo getInstance() {
        return LocalDataPartitionTableHolder.INSTANCE;
    }

    public synchronized void init(Map<String, List<DataRegionId>> regionInfos)
            throws IllegalPathException {
        partitionTableMap = new ConcurrentHashMap<>();
        for (Map.Entry<String, List<DataRegionId>> entry : regionInfos.entrySet()) {
            String storageGroupName = entry.getKey();
            List<DataRegionId> regionIds = entry.getValue();
            LocalDataPartitionTable table = new LocalDataPartitionTable(storageGroupName, regionIds);
            partitionTableMap.put(new PartialPath(storageGroupName), table);
        }
    }

    public synchronized void clear() {
        if (partitionTableMap != null) {
            partitionTableMap.clear();
            partitionTableMap = null;
        }
    }

    public DataRegionId getDataRegionId(PartialPath storageGroup, PartialPath path) {
        if (!partitionTableMap.containsKey(storageGroup)) {
            return null;
        }
        LocalDataPartitionTable table = partitionTableMap.get(storageGroup);
        return table.getDataRegionId(path);
    }

    /**
     * Try to allocate a data region for the new time partition slot. This function will try to create
     * new data region to make expansion if the existing data regions meet some condition.
     *
     * @param storageGroup The path for the database.
     * @param path         The full path for the series.
     * @return The data region id for the time partition slot.
     */
    public DataRegionId allocateDataRegionForNewSlot(PartialPath storageGroup, PartialPath path) {
        LocalDataPartitionTable table = partitionTableMap.get(storageGroup);
        return table.getDataRegionWithAutoExtension(path);
    }

    public List<DataRegionId> getDataRegionIdsByStorageGroup(PartialPath storageGroup) {
        if (partitionTableMap.containsKey(storageGroup)) {
            LocalDataPartitionTable partitionTable = partitionTableMap.get(storageGroup);
            return partitionTable.getAllDataRegionId();
        }
        return Collections.emptyList();
    }

    public synchronized void registerStorageGroup(PartialPath storageGroup) {
        if (partitionTableMap.containsKey(storageGroup)) {
            return;
        }
        partitionTableMap.put(storageGroup, new LocalDataPartitionTable(storageGroup.getFullPath()));
    }

    public synchronized void deleteStorageGroup(PartialPath storageGroup) {
        LocalDataPartitionTable partitionTable = partitionTableMap.remove(storageGroup);
        if (partitionTable != null) {
            partitionTable.clear();
        }
    }
}
